package com.yyyyy.java.util.java.java;

public class circle {
    double r;

    public void area(){
        double pai = 3.14;
        double s = pai*r*r;
        System.out.println("面积为"+s);


    }

    public double area2 (double pai){
        double s = pai*r*r;
        return s;

    }




}
